Patent application title: MOLDING APPARATUS AND INJECTION MOLDING METHOD USING THE SAME

Abstract:

A molding apparatus and an injection molding method using the same are
provided. A plurality of lower mold cores are arranged in a first
direction, and a plurality of upper mold cores are arranged in a row in
the first direction. At least one of the lower mold cores is movable into
contact with the upper mold cores.

Claims:

1. A molding apparatus, comprising:a plurality of lower mold cores
arranged in a first direction; anda plurality of upper mold cores
arranged in a row in the first direction,wherein at least one lower mold
core is moveable to a first position corresponding to a first upper mold
core and to a second position corresponding to a second upper mold core.

2. The molding apparatus of claim 1, further comprising:a mold support;a
core base on the mold support and movable in the first direction, the
core base containing the lower mold cores; anda driver in the mold
support to move the core base in the first direction.

3. The molding apparatus of claim 2, wherein the driver comprises:one of
an oil hydraulic cylinder and a driving motor installed in the mold
support; anda rod having an end fixed to the core base and extending
along the first direction,wherein the rod moves in the first direction in
response to operation of the one of the oil hydraulic cylinder and the
driving motor.

4. The molding apparatus of claim 1, wherein a frame molded by bringing
one of the upper mold cores and one of the lower mold cores into contact
with each other is detached from one of the contacted upper and lower
mold cores, while being inserted in the other of the contacted upper and
lower mold cores, when the contacted upper and lower mold cores are
separated from each other.

5. The molding apparatus of claim 1, wherein the lower mold cores and the
upper mold cores are sequentially brought into contact with each other
while the lower mold cores move in the first direction, a frame is molded
by pre-arranging a window in one of the first lower mold core and the
first upper mold core that are initially brought into contact while the
window is attached to the frame, and a keypad is attached to the frame by
bringing the first upper mold core and a second lower mold core into
contact with each other with the frame being inserted in the first upper
mold core.

6. The molding apparatus of claim 5, wherein the keypad is attached and
sealed to the frame by arranging the pre-molded keypad in the second
lower mold core, bringing the first upper mold core and the second lower
mold core into contact with each other, introducing resin between contact
surfaces of the keypad and the frame, and hardening the resin.

7. An injection molding method, comprising:performing a first molding step
for molding a frame by bringing a first lower mold core and a first upper
mold core into contact with each other, the first lower mold core being
one of a plurality of lower mold cores arranged in a row in a first
direction, and the first upper mold core being one of a plurality of
upper mold cores arranged in a row in the first direction; andperforming
a second molding step by bringing the first lower mold core and a second
upper mold core into contact with each other while the frame is
positioned in the first lower mold core, or by bringing the first upper
mold core and a second lower mold core into contact with each other while
the frame is positioned in the first upper mold core.

8. The injection molding method of claim 7, before the first molding step,
further comprising:performing a first arrangement step for arranging the
lower mold cores in a row in the first direction to be movable in the
first direction; andperforming a second arrangement step for arranging
the upper mold cores to be movable in a second direction perpendicular to
the first direction so that at least one of the lower mold cores can be
selectively moved to a contact position with the upper mold cores.

9. The injection molding method of claim 8, wherein the first arrangement
step comprises mounting a core base to be moveable in the first direction
on a mold support, the core base containing the lower mold cores.

10. The injection molding method of claim 9, wherein the first arrangement
step further comprises:installing one of an oil hydraulic cylinder and a
driving motor a rod having an end fixed to the core base in the mold
support,the rod moving in the first direction according to the operation
of the one of the oil hydraulic cylinder and the driving motor.

11. The injection molding method of claim 7, wherein the first molding
step comprises pre-arranging a window in one of the first lower mold core
and the first upper mold core and attaching the window to the frame while
molding the frame.

12. The injection molding method of claim 7, wherein the second molding
step comprises bringing the first lower mold core with the frame and the
second upper mold core into contact with each other by moving the lower
mold cores in the first direction and molding a coating on a surface of
the frame to be attached to the surface of the frame.

13. The injection molding method of claim 7, wherein the second molding
step comprises bringing the first upper mold core with the frame and the
second lower mold core into contact with each other by moving the lower
mold cores in the first direction and attaching a keypad to the frame,
wherein the keypad is in an already molded state and is inserted in the
second lower mold core before the first upper mold core and the second
lower mold core are brought into contact with each other.

14. The injection molding method of claim 13, wherein the second molding
step further comprises introducing resin between contact surfaces of the
frame and the keypad and hardening the resin to attach and seal the
keypad to the frame.

15. The injection molding method of claim 8, wherein:the first arrangement
step comprises arranging the lower mold cores including a first lower
mold core and a second lower mold core;the second arrangement step
comprises arranging the upper mold cores including a first upper mold
core and a second upper mold core;the first molding step comprises
arranging a pre-molded window in one of the first upper mold core and the
first lower mold core, bringing the first lower mold core and the first
upper mold core into contact with each other, and molding a frame with
the pre-molded window attached; andthe second molding step comprises
bringing the first lower mold core with the frame and the second upper
mold core into contact with each other, molding a coating, and attaching
the coating to an outer circumferential surface of the frame.

16. The injection molding method of claim 8, wherein:the first arrangement
step comprises arranging the lower mold cores including a first lower
mold core and a second lower mold core;the second arrangement step
comprises arranging the upper mold cores including a first upper mold
core and a second upper mold core;the first molding step comprises
arranging a pre-molded window in the first upper mold core, bringing the
first lower mold core and the first upper mold core into contact with
each other, and molding a frame with the pre-molded window attached;
andthe second molding step comprises bringing the first upper mold core
with the frame and the second lower mold core into contact with each
other and attaching a keypad to the frame, wherein the keypad is in an
already molded state and is inserted in the second lower mold core before
the first upper mold core and the second lower mold core are brought into
contact with each other.

17. The molding apparatus of claim 1, wherein the lower mold cores are
movable in the first direction, and the upper mold cores are movable in a
second direction, the second direction being perpendicular to the first
direction.

Description:

CROSS-REFERENCE TO RELATED APPLICATION

[0001]This application claims priority from and the benefit of Korean
Patent Application No. 10-2007-89946, filed on Sep. 5, 2007, which is
hereby incorporated by reference for all purposes as if fully set forth
herein.

BACKGROUND OF THE INVENTION

[0002]1. Field of the Invention

[0003]The present invention generally relates to a molding apparatus and
an injection molding method using the same. More particularly, the
present invention relates to an injection molding method for enabling
molding of a single product by a single molding apparatus and enabling
multi-shot injection molding using the molded single product.

[0004]2. Discussion of the Background

[0005]In general, injection molding is a synthetic resin molding
technology in which a mold is fabricated in the shape of an intended
injection-molded part and melted synthetic resin is filled in the mold
and cooled. Injection molding has a wide range of applications spanning
from simple products such as kitchen utensils to electronic devices such
as a home-use wired phone, an MP3 player, a portable phone, and an
electronic notepad.

[0006]Injection molding is widely used despite high mold fabrication costs
because it is favorable for mass production of standard products as it
provides products having constant quality, once a mold is fabricated.

[0007]Along with the development of the ultra high speed wired/wireless
Internet and mobile communication services, portable electronic devices,
for example, a portable phone, an electronic notepad, an MP3 player, and
a portable multimedia player, are proliferated, thus driving further
production of injection-molded products. Also, the popularity of portable
electronic devices has increased the demand for portable electronic
devices that can operate normally even under unfavorable environment
conditions in terms of dust, humidity, and temperature. Portable
electronic devices should also be waterproof so that they can operate
normally even in the rain.

[0008]A waterproof portable electronic device may have a seal, such as a
gasket, applied to the inner wall of a case or an additional waterproof
frame covering a circuit board within the case. Such a waterproof
portable electronic device is disclosed in U.S. Patent Application
Publication No. 2006/0050903 (Mar. 9, 2006). The waterproof portable
electronic device may be complex to fabricate and less portable because
of the thickness of its seal or its waterproof frame.

[0009]A non-waterproof portable electronic device may be carried in a
waterproof pack as disclosed in U.S. Patent Application Publication No.
2006/0274493 (Dec. 7, 2006). However, the waterproof pack should be
carried in addition to the non-waterproof portable electronic device,
which may be inconvenient.

SUMMARY OF THE INVENTION

[0010]The present invention provides a molding apparatus to facilitate
fabrication of the case of a waterproof electronic device and an
injection molding method using the same.

[0011]The present invention also provides a molding apparatus that may
provide for the miniaturization of electronic devices and an injection
molding method using the same.

[0012]The present invention also provides an injection molding method for
molding a plurality of parts to a single product without a separate
assembly process by multi-shot injection molding in a single molding
apparatus.

[0013]Additional features of the invention will be set forth in the
description which follows, and in part will be apparent from the
description, or may be learned by practice of the invention.

[0014]The present invention discloses a molding apparatus including a
plurality of lower mold cores arranged in a first direction, and a
plurality of upper mold cores arranged in a row in the first direction.
At least one lower mold core is moveable to a first position
corresponding to a first upper mold core and to a second position
corresponding to a second upper mold core

[0015]The present invention also discloses an injection molding method, in
which a first molding step includes molding a frame by bringing a first
lower mold core and a first upper mold core into contact with each other.
The first lower mold core is one of a plurality of lower mold cores
arranged in a row in a first direction, and the first upper mold core is
one of a plurality of upper mold cores arranged in a row in the first
direction. The method further includes a second molding step for
performing multi-shot injection molding by bringing the first lower mold
core and a second upper mold core into contact with each other while the
frame is positioned in the first lower mold core, or by bringing the
first upper mold core and a second lower mold core into contact with each
other while the frame is positioned in the first upper mold core.

[0016]It is to be understood that both the foregoing general description
and the following detailed description are exemplary and explanatory and
are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017]The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and constitute a
part of this specification, illustrate embodiments of the invention, and
together with the description serve to explain the principles of the
invention.

[0018]FIG. 1 is a flowchart showing an injection molding method using a
molding apparatus according to an exemplary embodiment of the present
invention.

[0019]FIG. 2A, FIG. 2B, and FIG. 2C sequentially show a first molding step
in the injection molding method shown in FIG. 1.

[0020]FIG. 3A, FIG. 3B, and FIG. 3C sequentially show a second molding
step in the injection molding method shown in FIG. 1.

[0021]FIG. 4A, FIG. 4B, and FIG. 4C sequentially show a third molding step
in the injection molding method shown in FIG. 1.

[0023]FIG. 5B shows an operation of the molding apparatus after the
ejection step in the injection molding method shown in FIG. 1.

[0024]FIG. 6 is a perspective view of an injection-molded part resulting
from the first molding step shown in FIG. 2A, FIG. 2B, and FIG. 2C.

[0025]FIG. 7 is a perspective view of an injection-molded part resulting
from the second molding step shown in FIG. 3A, FIG. 3B, and FIG. 3C.

[0026]FIG. 8 is a perspective view of an injection-molded part resulting
from the third molding step shown in FIG. 4A, FIG. 4B and FIG. 4C.

[0027]FIG. 9 is a perspective view of a case for a portable electronic
device, fabricated with the injection-molded parts formed by the
injection molding method shown in FIG. 1.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0028]The invention is described more fully hereinafter with reference to
the accompanying drawings, in which embodiments of the invention are
shown. This invention may, however, be embodied in many different forms
and should not be construed as limited to the embodiments set forth
herein. Rather, these embodiments are provided so that this disclosure is
thorough, and will fully convey the scope of the invention to those
skilled in the art. In the drawings, the size and relative sizes of
layers and regions may be exaggerated for clarity. Like reference
numerals in the drawings denote like elements.

[0029]It will be understood that when an element or layer is referred to
as being "on" or "connected to" another element or layer, it can be
directly on or directly connected to the other element or layer, or
intervening elements or layers may be present. In contrast, when an
element is referred to as being "directly on" or "directly connected to"
another element or layer, there are no intervening elements or layers
present.

[0030]FIG. 1 is a flowchart showing an injection molding method 10 using a
molding apparatus according to an exemplary embodiment of the present
invention. Referring to FIG. 1, the injection molding method 10
sequentially involves first and second arrangement steps (11) and (12),
first, second, and third molding steps (14), (15), and (16), and an
ejection step (18) to remove an injection-molded part.

[0031]In the first and second arrangement steps (11) and (12), molding
cores are arranged and set. Then the first, second, and third molding
steps (14), (15), and (16) can be repeated without performing the first
and second arrangement steps (11) and (12) unless a mold is worn away or
an intended product to be injection-molded is modified. Hence, now a
description will be made of the first, second, and third molding steps
(14), (15), and (16) and the first and second arrangement steps (11) and
(12) will be described in detail with reference to FIG. 2A.

[0032]In the first molding step (14), an already injection-molded part is
inserted and multi-shot injection molding is performed. FIG. 6 shows a
first frame 201a fabricated by the first molding step 14. The first frame
201a is a molded part of a front cover 201 of a portable electronic
device, as shown in FIG. 9. To be more specific, the first frame 201a is
molded with a window 213 attached to a frame 211 of the front cover 201.
The window 213 may be molded before the first molding step (14) and it
may be made of a transparent material so that a screen can be viewed.
With the pre-molded window 213 being inserted into the mold before
molding the first frame 201a, melted resin is introduced, thereby
simultaneously molding the frame 211 and attaching the window 213 to the
frame 211. Thus, waterproofing may be achieved between the window 213 and
the frame 211.

[0033]If the frame 211 is also made of a transparent material to allow a
user to view the screen, a film with a product brand or a communication
service provider logo printed therein may be inserted into the mold to
integrally mold the window 213 and the frame 211. The film inserted into
the mold may form the periphery of the screen along the edges of the
window 213.

[0034]As shown in FIG. 7, a second frame 210b is formed by applying a
coating 217 to the outer circumferential surface of the frame 211 in the
second molding step (15). The coating 217 is used to enhance the
appearance or tactile feeling of the outer circumferential surface of the
frame 211. The coating 217 may be made of a different material than the
frame 211. For example, if the frame 211 is made of a hard synthetic
resin, the coating 217 may be made of an elastomer resin to render it
soft. Also, the frame 211 and the coating 217 may be in different colors
to make a decorative effect on the outer looks of the frame 211. That is,
the second molding step (15) may decorate the injection-molded part with
multiple colors by multi-shot injection molding.

[0035]In the third molding step (16), a keypad 215 is attached to the
second frame 210b, as shown in FIG. 8. The keypad 215 is pre-molded and
inserted into the mold together with the second frame 201b and mold
alignment is performed. Then, the periphery of the keypad 215 is brought
into contact with the inner surface of the second frame 201b, while the
outer surface of the keypad 215 is exposed outward through an opening of
the second frame 201b. After mold alignment, resin is introduced between
the contact surfaces of the keypad 215 and the second frame 201b and
hardened. As a result, the keypad 215 is attached and sealed to the
second frame 201b, thereby waterproofing the connection between the
keypad 215 and the second frame 201b. The keypad 215 may be made of an
elastic material, such as silicon or urethane, so as to transfer user
input to a dome switch and return to its original position in the absence
of user input. Keys 219a and 219b of the keypad 215 may be hard
injection-molded parts that are attached to the keypad 215.

[0036]The use of multi-shot injection molding in attaching the window 213
and the keypad 215 to the frame 211 of the front cover 201 may make the
case of the portable electronic device waterproof without a separate
waterproofing process. While the coating 217 is molded in the second step
(15) and the keypad 215 is attached and sealed in the third molding step
(16), the attachment of the coating 217 and the keypad 215 are
independent of each other and thus there is no need to attach the coating
217 first and then the keypad 215 in this order. That is, the order in
which components are molded and attached to enhance the appearance, such
as the coating 217 as well as input/output components including the
window 213 and the keypad 215 in the frame 211, may vary depending on the
characteristics of a product.

[0038]Referring to FIG. 2A, in the molding apparatus 100, a plurality of
lower mold cores arranged in a first direction are installed to be
movable horizontally along its arrangement direction in the first
arrangement step (11), and a plurality of upper mold cores are arranged
in the first direction, to be movable in a direction perpendicular to the
movement direction of the lower mold cores in the second arrangement step
(12). When the upper mold cores move downward while the lower mold cores
remain still, at least one of the lower mold cores is brought into
contact with one of the upper mold cores. Each upper or lower mold core
is connected to a sprue 139. In the exemplary embodiment of the present
invention, sprues 139 are connected to the upper mold cores.

[0039]In FIG. 2A, the molding apparatus 100 is provided with two pairs of
lower mold cores and two pairs of upper mold cores. In accordance with
the exemplary embodiment of the present invention, an injection-molded
part, specifically the front cover 201 shown in FIG. 9 is fabricated
using only one pair of lower mold cores 121 and 123 and one pair of upper
mold cores 131 and 133. Hence, although the molding apparatus 100 shown
in FIG. 2A, FIG. 2B, FIG. 2C, FIG. 3A, FIG. 3B, FIG. 3C, FIG. 4A, FIG.
4B, FIG. 4C, FIG. 5A, and FIG. 5B is shown to have two pairs of lower
mold cores and two pairs of upper mold cores, reference numerals indicate
part of them.

[0040]The lower mold cores are mounted to be movable horizontally on a
mold support 101. While the lower mold cores may be installed to move
horizontally on their own, a first core base 102 to contain the lower
mold cores may be installed on the mold support 101 so that it may move
linearly. The lower mold cores are mounted in the first core base 102 and
arranged in the movement direction of the first core base 102. As the
first core base 102 moves horizontally, at least one of the lower mold
cores moves to a position where it faces one of the upper mold cores and
the facing lower and upper mold cores are brought into contact for
injection molding.

[0041]While an operator can manually move the first core base 102 to a
desired position, the first core base 102 may alternatively be moved to a
position by use of a separate driver.

[0042]The driver is operated by an oil hydraulic cylinder 104 or a driving
motor (not shown). A rod 141 (shown in FIG. 4C) extending along the
movement direction of the first core base 102 is connected to the oil
hydraulic cylinder 104 or the driving motor. The rod 141 has an end fixed
to the first core base 102 and moves lengthwise along with the operation
of the oil hydraulic cylinder 104 or the driving motor, thus moving the
first core base 102.

[0043]The second lower mold core 123 may move horizontally on the mold
support 101 to a position where it faces one of the upper mold cores of
the two pairs.

[0044]That is, the first core base 102 horizontally moves on the mold
support 101 from a first position where it faces one of the upper mold
cores to a second position where the second lower mold core 123 faces the
second upper mold core 133. The first core base 102 is at the first
position in FIG. 2A, FIG. 2B, and FIG. 2C and is at the second position
in FIG. 4A, FIG. 4B, and FIG. 4C.

[0045]To install the upper mold cores, the mold apparatus 100 is further
provided with a second core base 103. The second core base 103 moves up
and down, facing the mold support 101. The upper mold cores are arranged
in the arrangement direction of the lower mold cores and contained in the
second core base 103. Thus, the upper mold cores move perpendicularly to
the movement direction of the lower mold cores. An apparatus for lifting
the second core base 103 up and down is not shown.

[0046]At least one lower mold core is sequentially brought into contact
with a corresponding upper mold core, and different injection-molded
parts are produced according to the contacted mold cores and attached to
a pre-molded part. For molding another part and attaching it to the
pre-molded part, the pre-molded part may be transferred from the first
lower mold core 121 to the second lower mold core 123 or any other lower
mold core, or from the first upper mold core 131 to the second upper mold
core 133 or any other upper mold core. The transfer is possible by
maintaining the pre-molded part inserted in one of the upper or lower
mold cores.

[0047]That is, when the pre-molded part is hardened and the upper mold
cores are detached from the lower mold cores, the pre-molded part is
removed from the first lower mold core, while being inserted in the one
of the upper mold cores that is in contact with the first lower mold core
121, or the pre-molded part is removed from the upper mold cores, while
being inserted in the first lower mold core 121.

[0048]The injection molding method 10 using the molding apparatus 100 is
performed sequentially by the first arrangement step (11), the second
arrangement step (12), the first molding step (14), the second molding
step (15), and the third molding step (16). When needed, parts molded in
the molding steps may be changed. A final injection-molded part is
ejected in the ejection step (18) after the molding steps.

[0049]As described above, the lower mold cores are arranged to be movable
horizontally on the mold support 101 in the first arrangement step (11).
The lower mold cores with the shapes of intended injection-molded parts
patterned therein are mounted on the first core base 102 that moves
horizontally on the mold support 101.

[0050]In the second arrangement step (12), the upper mold cores are
contained in the second core base 102. The upper mold cores are arranged
in the direction in which the lower mold cores are arranged.

[0051]In the first and second arrangement steps (11) and (12), the
positions at which movement of the first core base 102 is to be stopped
are set. Thus, the preparation for injection molding is completed. Unless
the mold is worn away or a desired product is modified, the layout of the
upper and lower mold cores should not need to be changed. Therefore,
there is no need to repeat the first and second arrangement steps (11)
and (12) each time injection molding is performed.

[0052]In accordance with an exemplary embodiment of the present invention,
the window 213 to allow the screen to be viewed and the keypad 215 to
provide an input function are attached to the frame 211 in the front
cover 201 to be fabricated by the molding apparatus 100. Depending on the
product, the outer circumferential surface of the frame 211 may be coated
with the coating 217. The frame 211 has openings in which the window 213
and the keypad 215 are to be positioned.

[0053]FIG. 2A, FIG. 2B, and FIG. 2C sequentially show an injection molding
in the first molding step (14) and the resulting injection-molded part is
shown in FIG. 6.

[0054]During the first molding step (14), the frame 211 is molded and
simultaneously, the window 213 is attached to the frame 211. The first
lower mold core 121 is brought into contact with the upper mold core 131
to thereby mold the frame 211. The window 213 is pre-molded using a
transparent material, for example, acryl, and is pre-arranged in the
first upper or lower mold core 131 or 121, for multi-shot injection
molding.

[0055]When the window 213 is put in the first upper or lower mold core 131
or 121 and the first lower mold core 121 faces the first upper mold core
131, the second core base 103 descends so that the first lower and upper
mold cores 121 and 131 are in contact. Then, melted resin is introduced
in the cavity defined by the first lower and upper mold cores 121 and 131
through the sprue 139. As the resin is hardened, the frame 211 attached
with the window 213 is molded, as shown in FIG. 6. In the description of
the exemplary embodiment of the present invention, the injection-molded
part with the window 213 attached thereto is called the first frame 201a.
FIG. 2C shows a state where the first frame 201a is molded and then as
the second core base 103 goes up, the first lower mold core 121 is
opened.

[0056]During the second molding step (15), the coating 217 is molded and
attached to the first frame 201a. This step may be repeated according to
the number of molded parts to be attached to the first frame 201a. The
exemplary embodiment of the present invention takes the coating 217 as an
example of a molded part to be attached to the first frame 201a.
Depending on a product, decorative parts may be molded and attached
around a receiver or the keypad.

[0057]FIG. 3A and FIG. 3B sequentially show molding of the coating 217 in
the second molding step (15). The coating 217 is coated on the outer
circumferential surface of the first frame 201a, except in the region of
the window 213, to enhance the looks of an electronic device, such as a
portable phone. The shape of the circumferential surface of the front
cover 201 is formed by the upper mold cores. With the first frame 201a in
the first lower mold core 121, the coating 217 is molded by the second
upper mold core 133.

[0058]That is, when the first frame 201a is completely molded, the lower
mold cores are opened and the first core base 102 is moved horizontally.
Then, the coating 217 is molded by bringing the first lower mold core 121
into contact with the second upper mold 133. While the first frame 201a
is kept in the first lower mold core 121, the first lower mold core 121
is brought into contact with the second upper mold core 133 and melted
resin is introduced into the cavity between the first lower mold core 121
and the second upper mold core 133, thus molding the coating 217.

[0059]The first frame 201a with the coating 217 applied thereto is shown
in FIG. 7. The injection-molded part with the coating 217 is called the
second frame 201b. After the coating 217 is molded, the keypad 215 may be
attached. The keypad 215 is molded separately from the second frame 201b
and attached onto the inner circumferential surface of the second frame
201b in one of the openings of the second frame 201b. When the lower mold
cores are opened after the molding of the second frame 201b, the second
frame 201b is inserted into the second upper mold core 133. Hence, the
second frame 201b is not shown in FIG. 3C.

[0060]FIG. 4A, FIG. 4B, and FIG. 4C sequentially show the process of
attaching the keypad 215 to the second frame 201b in the third molding
step (16). The third molding step (16) is similar to the second molding
step (15), but the lower mold core used in the third molding step (16) is
different from the lower mold core used in the second molding step (15).
In FIG. 4A, the pre-molded keypad 215 is positioned in the second lower
mold core 123. Here, the second frame 201b remains inserted in the second
upper mold core 133 as a result of the second molding step (15).

[0061]When the second core base 103 moves up with the second frame 201b
inserted in the second upper mold core 133, the first core base 102 moves
horizontally, thus moving the second lower mold core 123 to face the
second upper mold core 133, as shown in FIG. 4A. Here, the pre-molded
keypad 215 is positioned in the second lower mold core 123.

[0062]When the second lower and upper mold cores 123 and 133 are brought
into contact, the keypad 215 is positioned in one of the openings of the
second frame 201b, and melted resin is introduced and hardened between
the periphery of the keypad 125 and the second frame 201b. As a
consequence, the keypad 215 and the second frame 201b are sealed
together, which may allow them to be waterproof.

[0063]FIG. 4C shows a state where the lower mold cores are opened with the
keypad 215 attached to the second frame 201b, and FIG. 8 shows the second
frame 201b with the keypad 215 attached thereto. Hereinbelow, the
injection-molded part with the molded keypad 215 attached thereto is
referred to as a third frame 201c.

[0064]While it has been described above that the attachment of the keypad
215 to the second frame 201b is performed by positioning the keypad 215
in the second lower mold core 123 and then bringing the second upper mold
core 133 into contact with the second lower mold core 123, it may be
further contemplated that the keypad 215 is positioned to be assembled to
the second frame 201b rather than positioned in the second lower mold
core 123, the second lower mold core 123 is brought into contact with the
second upper mold core 133, and then the keypad 215 is sealed in the
second frame 201b.

[0065]Depending on the number of parts to be attached to the frame 211 and
its attachment scheme, the first, second, and third molding steps (14),
(15), and (16) are repeated, and other molded parts may be attached to
the third frame 201c by changing which lower and upper mold cores are in
contact. For example, a decorative part may be inserted into a product,
for injection molding.

[0066]As shown in FIG. 9, the keys 219a and 219b may be separately molded
for the keypad 215 of the front cover 201. After being molded separately,
the keys 219a and 219b are attached to the third frame 201c. The keys
219a and 219b may include a search key to invoke a menu and search for
information, a start key, an end key, or a hot key to invoke a multimedia
function. The keys 219a and 219b also may provide a decorative effect to
the keypad 215.

[0067]FIG. 5A shows the ejection step (18) to remove the third frame 201c
from the molding apparatus 100. After the third frame 201c is removed
from the molding apparatus 100, the first core base 102 is moved
horizontally to the position where the first molding step (14) can be
performed, or to the position where the first arrangement step (11) may
be performed to arrange the lower and upper mold cores for to mold
another product, as shown in FIG. 5B.

[0068]As is apparent from the above description, the molding apparatus and
the injection molding method using the same according to exemplary
embodiments of the present invention arrange a plurality of lower mold
cores in a row to be movable horizontally so that they can be brought
into close contact with different upper mold cores according to their
positions. Therefore, different parts may be molded according to lower
and upper mold cores in close contact or another part can be attached to
a pre-molded part, thus facilitating fabrication of a case for a portable
electronic device. As the part tightly contacts the pre-molded part
simultaneously with its hardening, waterproofing may be achieved during
the molding.

[0069]Since the processes of molding a plurality of parts and attaching
them to a pre-molded part may be simultaneously carried out in a single
molding apparatus, fabrication cost may be reduced and fabrication of a
waterproof injection-molded product may be facilitated.

[0070]Furthermore, exemplary embodiments of the present invention may
obviate the need to carry a waterproof pack, thereby enhancing user
convenience.

[0071]For better understanding of the present invention, an exemplary
embodiment of the present invention has been described in the context of
fabricating a case of a portable phone as a portable electronic device,
in which the window is multi-shot injection-molded simultaneously with
molding of the frame of the case, and the coating, the keypad, and
decorative parts are inserted, sealed, and attached to the frame by
repeating the second molding step. Yet, the present invention is not
limited to fabrication of a portable phone. Rather, it is applicable to
molding of any product as long as the product includes a part fabricated
by injection molding, in addition to portable electronic devices
including an electronic notepad, a home-use wired phone, and a portable
multimedia player.

[0072]Also, while the case is completed by molding and attaching the
window, the keypad, and the coating to the frame of the case in the above
description, considering that the portable device can serve as an
accessory, other injection-molded parts may be attached as decorations to
the frame by injection molding according to exemplary embodiments of the
present invention.

[0073]It will be apparent to those skilled in the art that various
modifications and variations can be made in the present invention without
departing from the spirit or scope of the invention. Thus, it is intended
that the present invention cover the modifications and variations of this
invention provided they come within the scope of the appended claims and
their equivalents.